Girls just want to have fun. Or at least they don’t want to have as many babies as before. This is true in places like the United States, where a Western lifestyle has changed behavior, but also in other parts of the world where women are becoming more empowered and making the decision to have fewer children. Thus, the population around the world is aging.

Americans just don’t make babies like they used to. The U.S. birthrate is the lowest in nearly a century, according to a study released last year by the Pew Research Center. It’s half the level of the Baby Boom years after World War II. American women, on average, are likely to have fewer than two children during their lifetime, which means not enough babies are being born to maintain the current population size. Even among new arrivals, the trend is declining: The birthrate among Mexican immigrants to the U.S. has plummeted 23 percent since 2007.

This reproductive recession is not unique to America; it’s a global phenomenon. Women just about everywhere are having fewer kids and having them later in life. The world is about to get a lot older very fast.

This will present some challenges for economic growth, but the article explains that efficiencies could save us there.

More importantly, population explosion is one of the biggest challenges we have for the environment, so this trend could actually be a very good thing.